The larynx is a well-protected structure surrounded by mandible, sternum, and cervical spine. Its elasticity and mobility add to its protection. Laryngeal cartilages do not ossify before 20 years of age, but thereafter, the larynx can vary among individuals regardless of age.
The larynx has an important function in respiration, swallowing, and phonation. Minor trauma to larynx can disrupt these functions The significant impact of the injury on larynx can cause fracture and swelling leading to airway compromise.
A laryngeal fracture requires considerable impact force. Almost 80 to 90% of laryngeal injuries, fracture/dislocations, and separation usually result from significant high-velocity blunt trauma. The most common cause of laryngeal trauma is motor vehicle accident or sports injury, followed by penetrating neck injuries.
Schaefer reported 97% for laryngeal trauma was due to blunt trauma, and only one case had laryngeal trauma related to penetrating gunshot injury. Approximately 39% of blunt laryngeal trauma is caused by a sports injury, while physical assault comprises 33 % of blunt trauma. Hanging is another common cause of laryngeal trauma. Non-traumatic cause for laryngeal trauma is exceedingly rare.
Laryngeal trauma is rare. The incidence of laryngeal trauma ranges between 1 in 14000 and 1 in 30000 of emergency visits. Less than 1% of all cases seen at major trauma centers are diagnosed with laryngotracheal trauma and accounts for approximately one patient in 131,000 hospital admission. Laryngeal trauma is exceedingly rare in childhood compared to adulthood. Adult incidence is approximately 1 per every 30000 of emergency visits. The incidence of laryngeal cartilage fracture ranges from 0 to 67%.
The mortality rate is approximately 1% with a hospital stay of 13 days or longer if an injury is severe enough to warrant surgical intervention. Injuries involving the cricoid cartilage can have a mortality rate of as high as 40% because of asphyxia from airway obstruction. There is rapid airway obstruction as cricoid cartilage is a complete ring that cannot accommodate any degree of swelling or hematoma.
Following trauma to the larynx, swelling usually occurs within 6 hours post-trauma. Swelling can compromise the airway.
Anterior direct trauma appears to cause the most severe injury to larynx. In the younger age group, the elastic nature of cartilage may result in damage to the soft tissue rather than cartilage itself. The isolated fracture of the thyroid cartilage is the most frequent injury encountered, while fracture of the cricoid alone is very unusual. Almost 85% of the cricoid cartilage trauma cases are associated with tracheal cartilage involvement.
Bloom, Carvalho, and Kearns explained the difference between the mechanism of laryngeal trauma in adults and children. Laryngeal trauma is exceedingly rare in children due to anatomical and behavioral variation. Anatomically, the pediatric larynx is at the level of C4, thus protected by the mandible. Children also have relatively elastic cartilage and lack of ossification compared to an adult, which make it less likely to fracture. There are four varieties of laryngeal fractures described:
In all major trauma patients, especially MVA, assault, and sports injury, the clinician should be highly suspicious because there is a very high chance of missing laryngeal injury. The most common presenting symptoms are stridor, respiratory distress, dysphonia, dysphagia, odynophagia, and hemoptysis.
The most common presentation is hoarseness (85%), followed by dysphagia (52%). The common signs of laryngeal injury/fracture are edema, crepitations, subcutaneous emphysema, loss of thyroid prominence, open neck wound, and palpable cartilage fracture. The most commonly used classification of laryngeal trauma in literature is Schaefer–Fuhrman classification; this is mainly based on clinical findings and comprises five groups.:
Another classification system based on anatomical site, mode, the structure involved, and degree is as follows:
Verschueren, Bell, et al. modified Schaefer's classification to add endoscopic and imaging findings and create a management guideline.
Clinical evaluation should always include an endoscopic examination of the larynx using fiberoptic endoscopy, or direct laryngoscopy under general anesthesia in addition to imaging modalities such as a CT scan and ultrasound. Early endoscopic evaluation can guide the clinician in securing the airway and establishing a surgical plan. A systematic approach of clinical suspicion, followed by flexible laryngoscopy to assess grading of injury and status of the airway, and then reconstructive computed tomography (CT) to assess the laryngeal framework, avoids missing laryngeal fracture and long-term co-morbidities.
In literature, the recommendation is to perform CT within 24 hours of trauma is suggested as laryngeal fractures are frequently underdiagnosed. Schaefer has suggested a CT scan for all patients with a potential laryngeal fracture, while others have recommended selective use of CT scans. According to Taku et al., it is imperative to perform a CT scan after laryngeal trauma as a clinical examination may not reveal the underlying fracture. Various clinical findings might include swelling, hematoma, or normal at times. Hence CT scan can change the course of treatment; this will allow early surgical intervention to fix the laryngeal fracture. Ultrasound can be useful to diagnose thyroid cartilage fracture.
The optimal timing of surgical intervention is controversial, but many proposed that early reconstruction of larynx post-trauma gives a better prognosis for phonation and decannulation. In contrast, some authors proposed that delay in treatment can provide a comparable outcome to early treatment in laryngeal trauma.
Securing the airway is the primary goal of early management. Intubation can be difficult and might lead to losing the airway if not performed with caution. Tracheostomy under local anesthesia is recommended if airway obstruction is severe.  management of laryngeal trauma based on Schaefer–Fuhrman classification can categorize according to the following :
The literature has recommended keeping a patient under close observation for at least 24 hours as airway edema can occur several hours after the trauma. Most of the literature in the past 20 years has recommended early exploration and reconstruction of the laryngeal framework. This approach will help to preserve laryngeal function, especially the sphincteric, airway, and phonatory function, as even a minimal displacement of fractures can disrupt normal phonation.
Conservative management consists of observation, head of the bed elevation, steam inhalation, voice rest, and IV corticosteroid.
Tracheostomy is always the recommended intervention if a patient needs surgical exploration. Disruption of the laryngeal framework is an indication for surgical intervention. As per Hwan et al., an average timing of reconstruction suggested in the literature is 5.6 days (3 to 10 days).
Surgical exploration and correction of fractures are possible using different materials such as mini-plates, 3-D plates, or bioresorbable plates, and Montgomery intralaryngeal stent. Other various types of materials used for internal fixation post laryngeal fracture reduction are thread, steel wires, and titanium plates.
Whenever a conventional method of titanium mini-plates fails, especially in unossified cartilage because of the lack of uniformity, Titanium mesh may merit consideration as a safe and reliable method to fix fractured laryngeal unossified cartilage. Titanium mesh can be adjusted freely into various shapes, sizes, and positions, even with the complicated types of fractures. The adaptation plates have replaced wire fixation techniques of the laryngeal framework reconstruction. Likewise, mini plates have been suggested over wire fixation by Lynkins and Pinczower.
Other modalities of treatment include resorbable plates. Various indications for endolaryngeal stent include failure of primary repair of the mucosa, disruption of the anterior commissure, and comminuted fractures.
Literature has reported relatively good outcomes and has used functional parameters to assess prognosis. In 62 to 85% of cases, there is a good voice outcome, with good airway outcomes achieved in 76 to 97% of cases. The better outcome occurred in people who were treated early compared to those who received delayed treatment.
Age has a direct influence on prognosis as an older patient tends to have poor outcomes, especially if over 70 years of age.
Complications subdivide into acute and chronic. Acute complications are upper airway obstruction and asphyxia, Recurrent laryngeal nerve injury, hematoma, infection, and death. Chronic complications are vocal cord paralysis, hoarseness, recurrent granulation formation, supraglottic stenosis, glottic stenosis, subglottic or tracheal stenosis, Recurrent laryngeal nerve dysfunction, and chronic aspiration.
Most patients achieve decannulation and stable airway without stenosis or granulation tissue. Some cases result in deglutition disorder.
Postoperative: steroids, antibiotics, and antireflux medications should be considerations. Repeat endoscopic examination may be required before extubation to minimize complications.
Early evaluation and management lead to better long-term outcomes. Patients should seek medical help following anterior neck injury associated with voice or airway symptoms even if transient.
Detailed history taking and meticulous examination are required to minimize the chances of missing a laryngeal fracture in a clinical setting. As laryngeal trauma is a matter of airway emergency, inter-departmental teamwork is needed. Proper communication between different teams managing laryngeal trauma is important to avoid delay or missing diagnosis. If there is any clinical suspicion, further evaluation with endoscopy and imaging is warranted to prevent delay in treatment and to avoid complications.
Patients surgically treated for laryngeal fractures need multidisciplinary input and long-term rehabilitation with follow up to achieve optimum laryngeal functions like swallowing and phonation.
|||Kuttenberger JJ,Hardt N,Schlegel C, Diagnosis and initial management of laryngotracheal injuries associated with facial fractures. Journal of cranio-maxillo-facial surgery : official publication of the European Association for Cranio-Maxillo-Facial Surgery. 2004 Apr [PubMed PMID: 14980586]|
|||Bell RB,Verschueren DS,Dierks EJ, Management of laryngeal trauma. Oral and maxillofacial surgery clinics of North America. 2008 Aug [PubMed PMID: 18603200]|
|||Türkmen S,Cansu A,Türedi S,Eryigit U,Sahin A,Gündüz A,Shavit I, Age-dependent structural and radiological changes in the larynx. Clinical radiology. 2012 Nov [PubMed PMID: 22938793]|
|||[PubMed PMID: 2221732]|
|||[PubMed PMID: 11129037]|
|||[PubMed PMID: 16386338]|
|||Schaefer SD, The acute management of external laryngeal trauma. A 27-year experience. Archives of otolaryngology--head & neck surgery. 1992 Jun [PubMed PMID: 1637537]|
|||Colombo E,Murruni G, [Etiopathogenesis and biodynamics of closed laryngo-tracheal injuries]. Acta otorhinolaryngologica Italica : organo ufficiale della Societa italiana di otorinolaringologia e chirurgia cervico-facciale. 1989 [PubMed PMID: 2700063]|
|||Gussack GS,Jurkovich GJ, Treatment dilemmas in laryngotracheal trauma. The Journal of trauma. 1988 Oct [PubMed PMID: 3172302]|
|||[PubMed PMID: 10448735]|
|||[PubMed PMID: 7114721]|
|||Simonsen J, Patho-anatomic findings in neck structures in asphyxiation due to hanging: a survey of 80 cases. Forensic science international. 1988 Jul-Aug [PubMed PMID: 3192138]|
|||[PubMed PMID: 23806730]|
|||Leopold DA, Laryngeal trauma. A historical comparison of treatment methods. Archives of otolaryngology (Chicago, Ill. : 1960). 1983 Feb [PubMed PMID: 6336938]|
|||Bent JP 3rd,Silver JR,Porubsky ES, Acute laryngeal trauma: a review of 77 patients. Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery. 1993 Sep [PubMed PMID: 8414560]|
|||[PubMed PMID: 2296072]|
|||[PubMed PMID: 6698449]|
|||Atkins BZ,Abbate S,Fisher SR,Vaslef SN, Current management of laryngotracheal trauma: case report and literature review. The Journal of trauma. 2004 Jan [PubMed PMID: 14749588]|
|||[PubMed PMID: 10984849]|
|||Heath KJ,Palmer M,Fletcher SJ, Fracture of the cricoid cartilage after Sellick's manoeuvre. British journal of anaesthesia. 1996 Jun [PubMed PMID: 8679368]|
|||Bloom DC,Carvalho DS,Kearns DB, Endoscopic repair of pediatric traumatic laryngeal injury. International journal of pediatric otorhinolaryngology. 2001 Sep 28 [PubMed PMID: 11551616]|
|||[PubMed PMID: 7171422]|
|||[PubMed PMID: 16413891]|
|||Liao CH,Huang JF,Chen SW,Fu CY,Lee LA,Ouyang CH,Wang SY,Kuo IM,Yuan KC,Hsu YP, Impact of deferred surgical intervention on the outcome of external laryngeal trauma. The Annals of thoracic surgery. 2014 Aug [PubMed PMID: 24961838]|
|||[PubMed PMID: 3713409]|
|||Sato T,Nito T,Ueha R,Goto T,Yamasoba T, Laryngeal fractures treated with titanium mesh fixation. Auris, nasus, larynx. 2019 Jun [PubMed PMID: 30145027]|
|||Nahum AM, Immediate care of acute blunt laryngeal trauma. The Journal of trauma. 1969 Feb [PubMed PMID: 5763327]|
|||[PubMed PMID: 5055086]|
|||Yen PT,Lee HY,Tsai MH,Chan ST,Huang TS, Clinical analysis of external laryngeal trauma. The Journal of laryngology and otology. 1994 Mar [PubMed PMID: 8169503]|
|||[PubMed PMID: 9790292]|
|||Hwang SY,Yeak SC, Management dilemmas in laryngeal trauma. The Journal of laryngology and otology. 2004 May [PubMed PMID: 15165303]|
|||Plant RL,Pinczower EF, Pullout strength of adaption screws in thyroid cartilage. American journal of otolaryngology. 1998 May-Jun [PubMed PMID: 9617925]|
|||Kirby BM,Wilson JW, Knot strength of nylon-band cerclage. Acta orthopaedica Scandinavica. 1989 Dec [PubMed PMID: 2624091]|
|||[PubMed PMID: 9617926]|
|||Butler AP,Wood BP,O'Rourke AK,Porubsky ES, Acute external laryngeal trauma: experience with 112 patients. The Annals of otology, rhinology, and laryngology. 2005 May [PubMed PMID: 15966522]|
|||[PubMed PMID: 20236793]|
|||[PubMed PMID: 10504017]|